<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>购物车</title>
    <style>
        
        table {
          width: 800px;
          border: 1px solid #e9e9e9;
          border-collapse: collapse;
          border-spacing: 0;
          align-items: center;
          margin-top: 100px;
          margin-left: 300px;
        }

        h2 {
          margin-left: 300px;
        }

        th {
          border: 1px solid #e9e9e9;
          background-color: #f7f7f7;
          color: #5c6b77;
          text-align: left;
          font-weight: 600;
          padding: 8px 16px;
        }

        td {
          border: 1px solid #e9e9e9;
          text-align: left;
          padding: 8px 16px;
        }

      </style>
      <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  </head>
<body>
    <div id="app">
      <div v-if="books.length">
        <table>
            <tr>
              <th></th>
              <th>书籍名称</th>
              <th>出版日期</th>
              <th>价格</th>
              <th>购买数量</th>
              <th>操作</th>
            </tr>
            <tr v-for="(item, index) in books">
              <td>{{ item.id }}</td>
              <td>{{ item.name }}</td>
              <td>{{ item.date }}</td>
              <td>{{ item.price}}</td>
              <td>
                <button @click="decrement(index)" :disabled="item.count <= 1">-</button>
                {{ item.count }}
                <button @click="increment(index)">+</button>
              </td>
              <td>
                <button @click="deleteBook(index)">移除</button>
              </td>
            </tr>
        </table>
        <h2>总价格：{{ fullprice  }} ￥</h2>
      </div>
      <h2 v-else>购物车为空</h2>
    </div>

    <script>
      const vm = new Vue({
        el: '#app',
        data: {
          books: [
            { id: 1, name: '《java编程思想》', date: '2020-9', price: 98.00, count: 1 },
            { id: 2, name: '《数据分析与数据原理》', date: '2019-2', price: 39.00, count: 1 },
            { id: 3, name: '《Hadoop权威指南》', date: '2019-10', price: 59.00, count: 1 },
            { id: 4, name: '《代码大全》', date: '2018-8', price: 128.00, count: 1 },
          ]
        },
        computed: {
          fullprice() {
            var fullprice = 0;
            for (var i = 0; i < this.books.length; i++) {
              fullprice += this.books[i].price * this.books[i].count
            };
            return fullprice;
          }
        },
        methods: {
          increment(index) {
            this.books[index].count++
          },
          decrement(index) {
            this.books[index].count--
          },
          deleteBook(index) {
            this.books.splice(index, 1)
          }
        }
      })
    </script>
  </body>
</html>
